23
INSTRUCTION BULLETIN—Reference Guide
CyTime
TM
Sequence of Events Recorder
IB-SER32e-02
Jan-2022
© 2010-2022 Cyber Sciences, Inc. All rights reserved.
Type 2 Buffer (Compatibility Mode)
To maintain backwards compatibility with some legacy devices, the CyTime SER sup-
ports an additional method for retrieving event records. The table below shows the
registers used (ID=1). The procedure is as follows:
1. Read coil (FC 01) at address 000001 until a “1” is returned.
2. Next, read holding register (FC 03) at address 400103 to get the total number
of events in buffer (0 to 22).
3. Then read holding registers 400111 through 400198 (or fewer if buffer con-
tains less than 22 events).
4. Once buffer contents read, write a “1” to coil at address 000002 (FC 05).
5. Begin reading coil 000001 again until value is set to “1”
6. Repeat process until all events are retrieved.
Register
Description
Type
Range
Notes
(ID = 1)
COMPATIBILITY REGISTERS
000001
Data buffer ready
bit (coil)
0 or 1
value of “1” indicates “ready”
000002
Data buffer acknowledge
bit (coil)
0 or 1
write “1” to clear buffer
400102
Buffer type
integer
2
400103
Number of events in buffer
integer
0 to 22
400111 to
400198
Event data (4 registers per event record)
bitmap,
32-bit int
–––
see table with event log
registers, reg 1 to 4
Note: with this method, only one master may
retrieve event records, since the event log is cleared
as events are read. This does not affect access to
event log using File Record Access method (FC 20)
described previously.
Table 3-4 – Compatibility Registers